Question: Solve for $y$ : $-1 = 23 + y$
Answer: Subtract $23$ from both sides: $ \begin{eqnarray} \\ \hphantom{-1 {- 23}} &\hphantom{=}& \hphantom{y} \\ -1 &=& 23 + y \\ \\ {-23} && {-23} \\ \end{eqnarray} $ $ \begin{eqnarray} \\ -1 {- 23} &=& y \\ \end{eqnarray} $ Simplify. $ y = -24$